Deficiencies in our knowledge of the complex hormonal control of, and interactions with, blood glucose and lipids in patients with childhood onset diabetes mellitus warrant the following investigations. Simultaneous measurement of blood glucose and lipids and the major carbohydrate and lipid regulatory hormones (growth hormone, corticoids, glucagon and "immunoreactive insulin" in blood, and epinephrine, norepinephrine and dopamine in urine) will be performed on timed serial samples obtained throughout 24 to 48 hour study periods. The groups of patients to be evaluated include well regulated diabetics, non-diabetic controls, "brittle" diabetics and diabetics with ketoacidosis due to infection or emotional stress. In order to systematically analyze the significance of the physiologic and biochemical data collected in the different diabetic and nondiabetic groups, a data bank of patient information which will contain serial multi-variable data sets organized on an intervention basis will be established. The multi-variable data sets will be analyzed by techniques of cluster analysis and time series trajectory analysis. The results of these studies will be utilized to formulate practical criteria for diagnosis and therapy of children with unstable forms of diabetes mellitus.